The myths that the human race are controlled by can not be changed by you or I stopping believing in them. These myths live in a collective mind.
So one non-believer can not change the world. If I choose to no longer believe in money, or law, or all the other things that the human race has created to control the masses, well that will have no impact on the collective acceptance.
However, if you or I can inspire others to reject a particular myth, then you can gradually, or even rapidly, change the world.
Then the question is what myth will you create to replace the myth that we no longer collectively believe in? As without myths we can not collaborate in complex large societies and avoid complete free-for-all chaos.
I think the alternative myth that is based on values, based on an ‘open minded’ take on all humans being equal and based on sharing, love, empathy and compassion, surely has to be worth a try.
After all as humans we’ve never tried that one.